Mo对燃烧合成非化学计量碳化钛基金属陶瓷的影响

对Ｍｏ对燃烧合成非化学计量碳化钛基金属陶瓷的组织和性能进行了研究，结果表明，当Ｃ／Ｔｉ为０．４５时，反应物中添加Ｍｏ使烧烧合成金属陶瓷的粘结相由六方结构的ａ－Ｔｉ逐渐转变为体心立方结构的β－Ｔｉ；Ｍｏ在碳化钛晶粒和晶间粘结相内都有分布，碳化物晶粒细化；金属陶瓷的抗弯强度和红硬性提高，室温硬度降低。     

Ti（C,N）基金属陶瓷的相界面过渡层

对Ｔｉ（Ｃ，Ｎ）基金属陶瓷的相界面过渡层进行了系统的研究．实验结果表明：金属陶瓷中Ｔｉ（Ｃ，Ｎ）硬质相周边存在明显的包覆层组织，它是一种过渡相；Ｔｉ（Ｃ，Ｎ）／Ｎｉ相界面没有固定的取向关系；Ｗ，Ｍｏ元素主要富集于相界面，且Ｔｉ，Ｎｉ，Ｗ，Ｍｏ元素在相界面具有成分梯度高分辨电镜观察发现，相界面过渡层厚约８－１０ｎｍ并由纳米晶组成．这种过渡层是金属陶瓷的一种比较理想的相界面结构．     

碳化钛基金属陶瓷的燃烧合成致密化

研究了用燃烧合成－压制工艺一步合成非化学计量碳化钛基金属陶瓷，结果表明，存在一最佳施压滞后时间，此时可获得最大密度的产物，Ｔｉ粉的氢含量低于利用产物致密化。最终产物密度随外加压力的增大而增加，当外加压力大于１００ＭＰａ后，增加趋势变缓。外加压力保持时间超过１ｍｉｎ后，产物密度并不增加，最终产物由非化学计量碳化钛和钛组成。     

Ti_3Al＋Nb在甲醇中沿相界的应力腐蚀SCIEI

研究了Ｔｉ－２４Ａｌ－ｌｌＮｂ合金中Ｔｉ３Ａｌ＋Ｎｂ金属间化合物在甲醇溶液中的应力腐蚀及室温氢致开裂的规律，探讨了组织结构的影响．结果表明，Ｔｉ３Ａｌ＋Ｎｂ在甲醇溶液中应力腐蚀敏感性很高，不向组织应力腐蚀断裂归一化门槛值为而ｋ（ＩＳＣＣ）／ＫＣ＝０．５３－０．６９；应力腐蚀裂纹止裂门槛值为Ｋ（ＩＳＣＣ）／Ｋ（ｌｉ）＝０．６１－０．７９．Ｔｉ３Ａｌ＋Ｎｂ在室温动态充氢时能发生氢致开裂，门槛值和应力腐蚀相近，但裂纹扩展速率或断裂时间比应力腐蚀要慢１－３个数量级．两者断口形貌也不相同．发现了相界应力腐蚀现象．对固溶后炉冷试样，当ＫＩ较低时，应力腐蚀裂纹优先沿α２／β相界形核和扩展，从而获得相界应力腐蚀断口．如固溶后空冷或ＫＩ较高，则不出现相界应力腐蚀．     

生产电解二氧化锰用钛合金阳极的抗钝化性能

研究了Ｔｉ－１．５Ｎｉ、Ｔｉ－０．５Ｆｅ、Ｔｉ－１．５Ｎｉ－０．５Ｃｕ、Ｔｉ－１．５Ｎｉ－０．５Ｆｅ－０．３Ｃｕ４种合金在９５℃，４０ｇ／Ｌ Ｈ２ＳＯ４＋８０ｇ／Ｌ ＭｎＳＯ４电解二氧化锰溶液中作阳极时的抗钝化性能。研究表明：以上４种合金都具有比ＴＡ２优异的抗钝化性能，ＴｉＮｉＦｅ的最为优异，在电流密度低于８０Ａ／ｍ＾２时，阳极表面不生成氧化膜，析出相Ｔｉ２Ｎｉ对提高抗钝化性起关键作用。ＴｉＮｉＦ     

颗粒TiC增强铸造Fe—Cr—Ni基复合材料的制备工艺和显微组织

用液态反应合成法制备了颗粒ＴｉＣ增强铸造Ｆｅ－２８Ｃｒ－１２Ｎｉ基复合材料，探讨了工艺参数对显微组织的影响，结果表明，该复合材料由０．２￣５μｍ的多面体形ＴｉＣ颗粒和α－Ｆｅ基体组成，ＴｉＣ分布均匀弥散，无连接现象。     

钼含量对Ti—Mo—TiC硬质烧结材料组织与性能的影响

Ｔｉ－ Ｍｏ－ ３５．Ｉｖｏｌ％ ＴｉＣ和 Ｔｉ－ Ｍｏ－４７．４ｖｏｌ％ＴｉＣ合金具有优良的耐蚀耐磨性,作为新型的金属陶瓷引人注目．它是一种ＴｉＣ_２相和ｇ－Ｔｉ相的两相合金,在ｐ－Ｔｉ相中固溶了大量的钼．但是钼对合金组织的影响还不明了,最佳的钼添加量也还不清楚．因此,制备了ＴｉＣ的比例固定在４７．４ｖｏｌ％,钼含量分别为０ｖｏｌ％,２．６ｖｏｌ％,５．３ｖｏｌ％,８．ｓｖｏｌ％,１６．４ｖｏｌｏ, ２７ｖｏｌ％,余量为钛的合金,来对钼的作用进行研究． 本系合金采用粉末冶金的元素混合法制备．用市售的Ｔ…     

快速凝固Al—3.18Ti—0.65C合金中TiC相的形成和分布特征

采用快速凝固技术在Ａｌ－３．１８Ｔｉ－０．６５Ｃ（ｗｔ－％）合金中获得了呈弥散分布的单一ＴｉＣ相颗粒，尺寸为３０－１００ｎｍ，原子组成为ＴｉＣ０．７６，结合常规和快速凝固组织的分析对比，并以热力学分析为基础，研究和探讨了ＴｉＣ相的形成过程和机制。     

Al-Ti-C中间合金细化剂的组织及其细化性能

以一析方法在低温、低搅拌条件下成功地制备了几种成分的Ａｌ－Ｔｉ－Ｃ中间合工采用Ｘ射线衍射（ＸＲＤ）,扫措电镜（ＳＥＭ）和能谱分析（ＥＤＳ）等手段对中间合金的相组成和显微组织进行了综合分析,结果表明,Ａｌ－Ｔｉ－Ｃ中间合中的第二相粒子为块状Ａｌ３Ｔｉ和亚微米尺寸的非整化合物ＴｉＣｘ,其中ｘ在０．４９～０．７８之间不等,细化结果表明。Ａｌ－Ｔｉ－Ｃ对工业纯铝具有良好的晶粒细化效果,细化的闰核心为Ｔｉ,     

非化学计量比贮氢合金M1（Ni0.71Co0.15Al0.06Mn0.08）x的？…

研究了化学配比ｘ对贮氢合金Ｍ１（Ｎｉ０．７１Ｃｏ０．１５Ａｌ０．０６Ｍｎ０．０８）ｘ（４．６≤ｘ≤５．２）的结构、组织、电化学性能和ｐ－ｃ－Ｔ特性的影响。结果表明,随着ｘ增大非化学计量比合金点阵常数ａ值减小,ｃ值增大,单胞体积减小,当ｘ＝５．２时ｃ／ａ达到最大值。ｘ＝５．０的化学计量比合金具有最小的点阵常数和单胞体积。放电容量、充放电循环稳定性和ｐ－ｃ－Ｔ曲线平台压均随着ｘ增大而提高,当ｘ＝５．２     

烧结温度对(Ti, W, Mo, Nb)(C, N)-(Co, Ni)金属陶瓷组织结构和性能的影响

本文以(Ti,W,Mo,Nb)(C,N)-(Co,Ni)基金属陶瓷材料为研究对象,研究烧结温度对金属陶瓷的成分、微观组织和力学性能的影响,初步探讨成分、微观组织与材料强度的关系。研究结果表明：烧结温度对(Ti,W,Mo,Nb)(C,N)-(Co,Ni)基金属陶瓷组织特征有显著的影响;合金的总碳(Ct%)随着烧结温度的提高而降低,当烧结温度达到1490℃时,合金总碳的急剧降低,导致合金组织中出现脱碳相(η相),从而使得合金的硬度(HV₃₀) 、断裂韧性(KIC)和抗弯强度(TRS)降低;1470℃烧结温度下,(Ti,W,Mo,Nb)(C,N)-(Co,Ni)基金属陶瓷合金的硬度(HV₃₀) 、断裂韧性(KIC)和抗弯强度(TRS)的匹配最佳,表现为在实际应用工况下的综合切削性能最优。     

陶瓷相原始粉末粒度对Ti（C，N）基金属陶瓷组织和性能的影响

采用粉末冶金法制备了超细晶Ti（ C, N）基金属陶瓷和纳米改性Ti（ C, N）基金属陶瓷试样和刀具。研究了陶瓷相粉末粒度对Ti（ C, N）基金属陶瓷显微组织、力学性能及其刀具耐磨损性能的影响。结果表明,超细晶Ti（ C, N）基金属陶瓷和纳米改性Ti（ C, N）基金属陶瓷的硬质相均具有黑芯/灰壳和白芯/灰壳两种显微结构。超细晶Ti（ C, N）基金属陶瓷中白芯/灰壳结构硬质相晶粒较多,而纳米改性Ti（ C, N）基金属陶瓷中硬质相晶粒主要为黑芯/灰壳结构。与超细晶Ti（ C, N）基金属陶瓷相比,纳米改性Ti（ C, N）基金属陶瓷具有较高的抗弯强度和断裂韧度以及较低的硬度和孔隙度。纳米改性Ti（ C, N）基金属陶瓷刀具具有较长的使用寿命,约为超细晶Ti（ C, N）基金属陶瓷刀具使用寿命的2．3倍。     

Ti(C,N)基金属陶瓷刀具的切削性能

利用真空烧结工艺和表面氮化处理工艺制备纳米复合Ti(C,N)基金属陶瓷可转位刀片和功能梯度可转位刀片,并对刀片的切削性能进行分析。结果表明:切削正火态45#钢、淬火态45#钢和奥氏体不锈钢时,与YT15、YG8、TN20相比,制备的刀具皆表现出较优的切削性能和较高的耐磨性,表面经氮化处理后,刀具的表面硬度提高了HRA2.2,大幅度提高了刀具的抗热冲击性能。具有梯度结构的金属陶瓷刀片切削正火钢、铸铁和不锈钢时的切削性能比无梯度结构金属陶瓷刀片的切削性能优良,具有更高的耐磨性。     

纳米TiN改性金属陶瓷刀具的磨损性能

Ti(C,N)基金属陶瓷由于具有优良的综合性能因而被广泛用作刀具材料。本文探讨了纳米 Ti N对 Ti C基金属陶瓷刀具显微组织的影响 ;还研究了它与 Ti(C,N)基金属陶瓷刀具 (cermetμm,下同 )及 YG8刀具在切削灰铸铁时的磨损曲线及磨损机理。结果表明 ,纳米 Ti N改性 Ti C基金属陶瓷刀具 (cerm etnm,下同 )的效果显著 ;与 cermetμm刀具及 YG8刀具相比 ,cermetnm刀具具有更高的寿命与耐磨性 ;崩刃是 cermetnm刀具主要的失效形式     

Effect of carbon content on the microstructure and properties of (Ti0.7W0.3)C-Ni cermet

(Ti_0.7W_0.3)C solid solution powder was synthesized by high-energy ball milling. We investigated the effect of excess carbon in this system on the microstructure, pore level, and mechanical properties of (Ti_0.7W_0.3)C?-20 wt.% Ni cermet. We also report the variations in the carbon stoichiometry of the (Ti_0.7W_0.3)C_x phase in the powder and in the (Ti_0.7W_0.3)C_x?-20 wt.% Ni cermet after carbothermal reduction and liquid phase sintering, respectively. The particle size of the solid-solution carbide decreased with increasing carbon content in the (Ti_0.7W_0.3)C-?20 wt.% Ni cermets. This occurred because the dissolution of the solid solution (Ti,W)C is hindered by the high activity of carbon. However, an increase in the carbon content generated pores and carbon segregation, resulting in poor mechanical properties, as also observed in other carbide cermets.     

Early high-temperature oxidation behavior of Ti(C,N)-based cermets with multi-component AlCoCrFeNi high-entropy alloy binder

The early high-temperature oxidation behavior of Ti(C,N)-based cermets with equiatomic AlCoCrFeNi high-entropy alloy binder has been studied, as well as the cermet with Ni/Co binder as a reference. Experiments were performed at the temperature range of 800–1100 °C in static laboratory air. The micro-structural evolution of the multi-layered oxide scales on the cermets was investigated and the effect of binder phase constituent on the oxidation characteristics of Ti(C,N)-based cermets was evaluated. The results demonstrated that the cermet with AlCoCrFeNi multi-element alloy binder possesses superior oxidation resistance, which is greatly better than that of the cermet with Ni/Co metallic binder under the same condition. We suggest that the formation of a continuous and dense external oxide scale can effectively impede the outward diffusion of volatile tungsten oxides and inward oxygen transport, leading to a remarkable improvement of oxidation resistance. In addition, the enhanced oxidation resistance was related to the high Cr and Al concentration in AlCoCrFeNi binder phase that urges the formation of oxide layers with more efficient passivation effect against oxidation.     

钼含量对Ti（C，N）-Co金属陶瓷抗热震性能的影响

采用真空烧结工艺,以纳米TiN、亚微米TiC等陶瓷粉体作原材料,以金属钴作粘结剂,并添加不同含量钼,制备了Ti（C,N）-Co金属陶瓷。采用扫描电镜研究了Ti（C,N）-Co金属陶瓷的组织,测量了力学性能,采用压痕．急冷法研究了抗热震性能。结果表明,随着热震温度的升高和热循环次数的增加,金属陶瓷中的裂纹增长;钼含量较低的Ti（C,N）-Co金属陶瓷抗热震性能较好。     

Effect of carbon content and cooling mode on the microstructure and properties of Ti(C,N)-based cermets

Ti(C,N)-based cermets were prepared by vacuum liquid sintering. The effects of carbon content as well as cooling mode on the microstructure, magnetic and mechanical properties of the cermets were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). Hardness and transverse rupture strength (TRS) were also measured. The grains of Ti(C,N)-based cermets became finer and solid solubility of titanium, molybdenum, tungsten in binder phases decreased with increasing carbon content. The thickness of the rim phases increased when the cermet was annealed at 1360 °C for 30 min during cooling, which resulted in the decrease of the hardness and the transverse rupture strength (TRS). On the other hand, the magnetic saturation of Ti(C,N)-based cermets increased with increasing carbon content, which was due to the decrease of the solid solution of alloy elements in binder phases.     

High-quality Ti(C,N)-based cermets via solid-state nitrogen-pressure sintering: Influence of the sintering atmosphere

Owing to the denitrification behavior of Ti(C,N)-based cermets during the sintering process, nitrogen atmosphere sintering is essential for the fabrication of high-quality products. Disclosing the roles of the sintering atmosphere on the microstructure and properties of cermet is of significance. Herein, Ti(C,N)-based cermets were fabricated under six types of sintering atmosphere. Effects of sintering atmosphere on the microstructure, coercive force (Hc), specific saturation magnetization (Ms (%)), and mechanical properties of cermets were investigated. More rimless Ti(C,N) grains with increased fraction of black cores were formed with increasing the nitrogen partial pressure. Three types of gradient structure of cermets were confirmed caused by the different nitrogen activity at the liquid sintering state. Vacuum sintering induced the formation of thicker rims on smaller Ti(C,N) cores at the surface due to the low nitrogen potential, while fcc solid solutions rich in N was formed in nitrogen atmosphere. Vacuum sintered cermets showed the lowest Hc and Ms. (%) of 3.66 KA/m and 2.13%, owing to the denitrification process. High-quality Ti(C,N)-based cermets were achieved via the solid-state nitrogen atmosphere sintering, benefiting from the optimized core-rim structure, i.e. moderate thickness of rims and certain amount of black Ti(C,N) cores.     

Ti(C,N)基金属陶瓷材料显微结构与性能研究进展

对国内外近年来有关Ti(C,N)基金属陶瓷材料的显微结构与性能的研究成果进行了总结。首先,介绍了Ti(C,N)基金属陶瓷材料的发展史;Ti(C,N)基金属陶瓷的显微结构、力学性能,以及显微结构与其性能的关系等。其次,列举并比较了不同的烧结方法所制备的Ti(C,N)基金属陶瓷材料的力学性能;结果表明:微波烧结和放电等离子烧结技术在较低的温度就可以成功烧结高硬度、高抗弯强度与断裂韧性高的产品,但实际生产中,这类技术还没有广泛被应用,应用最广的是真空烧结方法。最后介绍了Ti(C,N)基金属陶瓷材料的今后的研究趋势。